The Dodge Challenger Message Board

I just read on one of the forums on the MMA site that if you don't have the two leads to the pickup coil the right way round in an electronic distributor that you won't get an accurate timing light reading. Is it right Only ask cos my SnapOn dial back timing light struggles to read my timing marks and tach readings are very erratic.

If the two pick-up wires are the wrong way around the coil will fire before it has fully charged up. So the spark will be weak. Main symptom will be missfiring under load.

This is because the ECU fires as the rotor approaches the pick-up instead of as it moves away from it.

Easy to tell if you have them the wrong way around. If you swap them around and the timing retards a lot they were wrong.
If you swap them around and the timing advances a lot, swap them back because they were right to start with.

If you have a multi-spark ignition most timing lights will struggle to understand the signal. That is probably your problem. I had to buy a new light when I had a MSD unit.

Pretty sure the wires are right way round cos no misfire, still got a little stumble when the secondarys open tho', but I'll check the wiring anyway. The amount of times I've stared at a wiring diagram since I fitted the Painless kit it should be right
Shame about me SnapOn timing light, it has an advance inc/dec button and I always thought it was well cool

On cars with MSD ignitions, I usually only set total timing at 3500 RPM for that exact problem. Hard to know exactly where you're at for initial timing though (but the lowest reading you can get is the right one).

EDIT : on cars with Crane Fireball ignition boxes, I've noticed these ignitions have a mode for setting the timing. That is, there's a mode in which they don't give multiple sparks.
Too bad MSD did not copy this...